Just The Facts

BRAIN/NERVOUS SYSTEM

Men have larger brains; women have more brain cells.

Men and women use different parts of their brains while thinking.

There are significant differences in the brain activity of men and women.

Male brain neurons are about a third larger than female neurons; male and female neurons take up significantly different amounts of dopamine–a brain chemical that acts as a mood enhancer, relieves pain and regulate motion.

Because of the later maturation in males of the part of the brain that weighs risks and moderates impulsive behavior, adolescent boys are more likely than girls to take life-threatening risks, commit suicide and die violently than girls of the same age.

Women experience more pain from pressure and electrical stimulation than men.

Males are more likely than females to identify binge eating as normal.

Parts of the hypothalamus are larger in heterosexual males than in transgender and homosexual males.

Women are more likely than men to recover their speech after a stroke.

HEART

Men have larger hearts; women’s hearts beat faster.

Heart disease presents differently in men and women: men feel a crushing pain in their chest; 15% of women experience fleeting pain in the upper abdomen or back, nausea, shortness of breath, and sweating.

When a woman reaches menopause, her risk for cardiovascular disease increases four-fold.

The electrical system of the heart is different in men and women: women have faster heart rates and a different electrocardiogram than a man.

The time for the heart to return to baseline after a beat is longer for women than men.

Men who are diagnosed with heart disease are typically ten years younger than women.

In general, coronary artery disease strikes men almost two decades earlier than it does women; most men with coronary artery disease are dead by the time they are 65.

Sudden cardiac death (death within an hour of the onset of symptoms) is more common in males.

Women are more likely to develop abnormally rapid heart rates, particularly in association with their menstrual periods.

Fifty nine percent of women but only 39% of men have strokes associated with high blood pressure.

Women are susceptible to potentially lethal arrhythmias when they take some of the very medication that stabilizes rhythm in men.

LUNGS

Even when corrected for body size, men’s lungs are bigger than women’s.

It is more dangerous for women to smoke than for men. For the same number of cigarettes smoked, women are 20 to 70 percent more likely than men to develop lung cancer.

A man takes 12 breaths per minute while a woman takes only nine breaths per minute on average.

Women are less prone to hiccups than men.

IMMUNE SYSTEM

Because they have more active immune systems, women have the ability to fight off viral infections better than men.

Men are more susceptible to parasitic infestations than women because of their higher levels of testosterone, which promotes parasite breeding rates.

DIGESTIVE SYSTEM

Dose for dose, women are more susceptible to intoxication from alcohol.

Food takes twice as long to pass through the digestive system of women compared with that of men.

Boys between 11 and 15 are more likely than their sisters to have iron deficiency anemias because girls absorb iron more easily from their gastrointestinal tracts than boys at that age.

Food leaves a man’s stomach a third faster than a woman’s, and liquids twice as quickly.

Women are more likely than men to feel overly full after eating and have more problems with bloating and gas immediately following a meal.

The composition of bile, which is made in the liver and stored in the gall bladder, is different between the sexes; some of the breakdown products of bile increase women’s risk for colon cancer and may also explain the twice-higher incidence of inflammatory diseases of the intestine in females, including Ulcerative Colitis and Crohn’s disease.

SKELETAL SYSTEM

Eighty percent of roughly 210,000 hip fractures each year occur in women.

Osteoporosis is less likely to occur in women with hypertension who are treated with a thiazide diuretic (Diuril): the drug helps preserve bone as well as reducing blood pressure because it tends to reduce the amount of calcium excreted in the urine.

Osteoporosis isn’t a disease of older women alone; back pain in an older man will prompt a savvy doctor to order a bone density test, just as he would for a woman.

Osteoporosis can occur in young adults with anorexia or bulimia.

MEDICATIONS

Differences in the liver’s drug processing system affect the way medicines are processed; women clear several medications faster than men, including the antibiotic erythromycin, prednisolone and diazepam (Valium).

There are sex-specific differences in the absorption and metabolism of pain-killing medications and anesthetics.

MORTALITY

Because of their greater biologic vulnerability and the fact that society assigns men the most dangerous jobs, men are six years younger than women when they die.

Boy babies are twice as likely to die before birth than girls. Although approximately 240 males are conceived for every 100 girls, the ratio of boys to girls at birth is 1.05 to 1.

CANCER

Women develop melanoma on different areas of the body than men. Skin cancer occurs more frequently on the ears and necks of men and on the legs of women probably due to the shorter hairstyles of men and the exposed legs of women, since they are almost always caused by exposure to the sun.

A typical colon cancer is located 10 to 20 percent higher up in the colon in women than in men. Cancers in the right colon are occurring more frequently than in the past. That’s why sigmoidoscopy, which visualizes only part of the descending colon, does not replace colonoscopy as a cancer detector.

Pancreatic cancer occurs three times more frequently in men than in women. Estrogen and progesterone appear to protect women from pancreatic cancer.

In both men and women, some cancers have receptors for estrogen and progesterone, and for patients whose cancers carry such receptors, survival rates are lower because circulating hormones attach to these receptors and impact the malignancy’s behavior.